Serotonine (5-HT) recognises several well defined cell surface receptors. Among these, 5-HT1A and 5-HT2A at which serotonine have high affinity, are known to be implicated in many Central Nervous System disorders such as sexual disorders, depression, anxiety, schizophrenia, Parkinson and neurodegenerative diseases (EP 0 526 434 B1; WO 01/21593 A1; WO 02/24661 A2; WO 02/24662 A1; WO 03/014079 A1; WO 03/013539 A1; WO 03/035072 A1; WO 05/102343 A1; WO 06/019715 A1; WO 06/010574 A1; WO 06/024471 A1.
In the previous art, several classes of compounds able to interfere with the neurotransmission at serotonine or dopamine receptor subtypes are known. Particularly, derivatives based on the core structure of the arylpiperazine and benzimidazolone have been described (e.g. GB 2023594, U.S. Pat. Nos. 3,472,854, 4,954,503 and WO 98/33784), and targeted both to generic serotonine or dopamine receptors and to a specific receptor subtype. In another patent (U.S. Pat. No. 5,576,318) compounds based both on the benzimidazolone and phenyl piperazine structures are described: in this latter case the described affinities are limited to 5-HT1A and 5-HT2A receptor subtypes. Further compounds with affinity to 5-HT recptors and their synthesis have been disclosed in WO 01/21593 A1.